最新回答 / tinylight
在這一章節中,我們只用到了create和update這兩種生成策略,create會自動建表,update不僅可以自動建表,還可以對表進行更新操作
2016-10-22
CREATE TABLE class
(
cid INT PRIMARY KEY,
cname VARCHAR(20) NOT NULL,
cremarks VARCHAR(20)
);
CREATE TABLE student
(
sid INT PRIMARY KEY,
sname VARCHAR(20) NOT NULL,
sremarks VARCHAR(20),
cid INT
);
ALTER TABLE student ADD FOREIGN KEY fk_student_cid (cid) REFERENCES class(cid);
(
cid INT PRIMARY KEY,
cname VARCHAR(20) NOT NULL,
cremarks VARCHAR(20)
);
CREATE TABLE student
(
sid INT PRIMARY KEY,
sname VARCHAR(20) NOT NULL,
sremarks VARCHAR(20),
cid INT
);
ALTER TABLE student ADD FOREIGN KEY fk_student_cid (cid) REFERENCES class(cid);
2016-10-14